B, Descriptive Geology, 64 Bulletin No. 257 C, Systematic Geology and Paleontology, 72 DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY CHARLES D. WALCOTT, DlRECTOB GEOLOGY AND PALEONTOLOGY OF THE JUDITH RIYER BEDS BY T. W. STANTON AND J. B. HATCHER WITH A CHAPTER ON THE FOSSIL PLANTS F. H. KISTOWLTON WASHINGTON GOVERNMENT PRINTING OFFICE 1905 CONTENTS. Page. Letter of transmittal...................................................... 7 introduction............................................................. 9 Descriptive geology....................................................... 11 The stratigraphic column ......'........................................ 11 Benton shales............................................ 11 Eagle formation.......................................... 12 Claggett formation ........................................ 13 Judith Eiver beds......................................... 13 Bearpavv shales .......................................... 13 Higher horizons.......................................... 14 Historical review......I........................:..............-....... 14 Description of Judith Eiver beds, by areas ............................. 31 Original area..................................................... 31 General features.............-..-..--..--..--.-.....-......... 31 Exposures on Dog Creek...................................... 34 Exposures on Birch Creek .................................... 38 Exposures on Missouri between Birch and Cow creeks.......... 40 Exposures on Cow Creek ...................................... 41 Area near Havre, Mont .............. .............'................ 45 Exposures on Milk River from Havre to the international boundary................................................... 48 Exposures on Milk Kiver north of the international boundary... 51 Sage Creek area, Assiniboia ....................................... 53 Willow Creek area, in central Montana ............................ 56 Fish Creek area......'............................................ 59 Other probable areas ............................................. 61 Resume and conclusions .................................'............. 62 Vertebrate fauna, by J. B. Hatcher........................................ 67 Pisces ..-....:...................--........-.-.---.,,............. ... 67. Amphibia ........................................................... 69 Reptilia ........................................................:.... 71 Aves ........................................... '. ..................... 99 Mammalia.... r ...................................................... .100 Summary............................................................ 101 Invertebrate fauna, by T. W. Stanton...................................... 104 Pelecypoda ........:................'................................. 104 Gasteropoda ..................... ................................... 113 Cephalopoda......................................................... 119 Insecta ............................................................... 119 General comments ................................................... 119 Fossil plants, by F. H. Knowlton.......................................... 129 Descriptions of species ................................................ 129 Discussion of the flora ................................................ 150 Index ................................................................... 169 3 ILLUSTRATIONS. Page. PLATE I. A, General view of the Eagle formation; B, Sandstones and overlying lignite-bearing beds of the Eagle formation at the mouth of Eagle Creek ........................................................ 12 II. Cliff of upper Eagle sandstone near mouth of Dog Creek ........... 36 III. A, General view of Birch Creek Canyon from top of bluffs near its mouth, looking toward the Bearpaw Mountains; B, Broken anti­ cline of Eagle sandstone on north side of Missouri River 1 mile below mouth of Birch Creek ................................... 38 IV. A, View down Missouri River below mouth of Birch Creek; B, Clag- gett formation and overlying Judith River beds on Birch Creek ... 40 V. Fault contact of highly inclined Eagle sandstone with horizontal Judith River beds near mouth of Cow Creek .................... 42 VI. A, Undisturbed Judith River beds with overlying Bearpaw shales on Cow Creek; B, Fault contact of Judith River beds with Bear- paw shales on Cow Creek 10 miles above its mouth.............. 44 VII. A, Indurated or concretionary mass in upper part of Judith River beds, Cow Creek 13 miles above its mouth; B, Upper part of Judith River beds with heavy bed of lignite, Cow Creek......... 44 VIII. A, Badlands exposures of Judith River beds, north side of Milk River near Havre, Mont.; B, Upper part of Judith River beds and overlying Bearpaw shales, south side of Milk River 3 miles west of Havre, Mont .......................................... 46 I.. A, Upturned Judith.River beds and base of Bearpaw shales, Meili Coulee near Havre, Mont.; B, Claggett shales and base of Judith River beds, Milk River one-half mile below Pendant d'Oreille, Assiniboia.................................................... 48 X. A, Exposure showing remains of Trachodon skeleton on Sage Creek, Assiniboia; B, Contact between Judith River beds and overlying Bearpaw shales on Sage Creek, Assiniboia....................... 54 XI. A, Judith River beds on Willow Creek 10 miles north of .Mussel- shell post-office, Mont.; B, Judith River beds on Fish Creek, Montana ..................................................... 58 XII. Fig. 1, Unio priscus Meek and Hay den; figs. 2-4, Unio priscus var. abbreviatus n. var............................................. 126 XIII. Fig. 1, Unio subspatulatus Meek and Hayden; figs. 2, 3, Unio supen- awensisn. sp.; fig. 4, Goniobasis judithensis n. sp.; fig. 5, Melania whiteavesi n. sp................................................ 128 XIV. Fig. 1, Fern, indeterminable, enlarged 3 times; fig. 2, Sequoia sp.?; figs. 3-5, Sequoia reichenbachi (Gein.) Heer; fig. 6, Osmunda montanensis n. sp.; enlarged 2times............................ 158 5 b ILLUSTRATIONS. Page. PLATE XV. Fig. 1, Cunninghamites elegans (Corda) Endlicher; figs. 2-5, Dam- mara acicularis n. sp.; fig. 6, Carpites pruni n. sp.; fig. 6a, Carpites pruni n. sp., enlarged 3£ times; fig. 7, Fern, indeterminable, enlarged 3 times ............................................ 160 XVI. Fig. 1, Cunninghamites pulchellus n. sp.; fig. 2, Carpites alatusn. sp.; fig. 3, Thuja cretacea? (Heer) Newberry; fig. 3a, Thuja cretacea? (Heer) Newberry, enlarged 3 times; fig. 4, Carpites judithse n. sp.; fig. 5, Sequoia heterophylla? Vel.; fig. 6, Cun­ ninghamites recurvatus ? Hosius and von der Marck........... 162 XVII. Figs. 1-5, Populus cretacea n. sp.; fig. 6, Quercus montana n. sp.; fig. 7, Sapindus inexpectans n. sp........ ..................... 164 XVIII. Fig. 1, Populites amplus n. sp.; fig. 2, Quercus n. sp.; fig. 3, Betu- lites? hatcheri n. sp.; figs. 4, 5, Diospyros judithae n. sp.; fig. 6, Phyllites dubius n. sp........................................ 166 XIX. Fig. 1, Populus sp.; fig. 2, Phyllites denticulatus n. sp.; fig. 3, Diospyros judithse n. sp.; fig. 4, Castalia stantoni n. sp.......... 168 FIG. L Boreodon matutinus Lambe........................................ 100 LETTER OF TRANSMTTTAL. DEPARTMENT OF THE INTERIOR, UNITED STATES GEOLOGICAL SURVEY, Washington, D. C. , May 11, 1904. SIR: I have the honor to transmit herewith the manuscript of a report on the geology and paleontology of the Judith River beds, by T. W. Stanton and J. B.-Hatcher, with a chapter on the fossil plants by F. H. Knowlton, and to recommend its publication as a bulletin. The report embodies the results, of field' studies in Montana and adjacent regions during the season of 1903, and of a subsequent study of the collections. By combining careful stratigraphic observations with several lines of paleontologic investigation the authors have satis­ factorily answered a much discussed question in Cretaceous stratig- raptry, and the results stated in this report will have an important bearing on the geology of a large area in the Northwest. Very respectfully, C. W. HAYES, Geologist in Charge of Geology. Hon. CHARLES D. WALCOTT, Director United States Geological Survey. GEOLOGY AND PALEONTOLOGY OF THE JUDITH RIVER BEDS. By T. W. STANTON and J. B. HATCHER." INTRODUCTION. During- the summer of 1903 we spent two months together in the field study of the Judith River and associated formations of north­ ern and central Montana and adjacent areas of Canada. The prin­ cipal results of this work were the accurate determination of the position of the Judith River beds in the Upper Cretaceous section, and the removal of all doubts as to the correlation of these beds with the Belly River beds of Canada, thus establishing more accurately the position of that Canadian formation. These results are offered as a slight contribution to the Mesozoic history of the north interior region, which is rendered more than usually difficult to decipher because land or nonmarine conditions prevailed during several recurring intervals, at least from the Upper Jurassic to the top of the Cretaceous. It is our purpose to give somewhat in detail the evidence on which our conclusions are based, restricting the descrip­ tions to the areas which have been actually studied by us and which include practically all the known exposures of Judith River beds in Montana and the southeastern part of